const o = {
  name: '吕布',
  age: 18,
  sex: '男'
}

const oDiv: HTMLDivElement | null = document.querySelector('div')

if(oDiv) {
  oDiv.style.display = 'block'
}

// let age: 7 | 9 | 18 | 188 = 188

// let age = 18

// let str1 = 'Hello TS'
// const str2: 'Hello TS' = 'Hello TS'


type TDir = 'up' | 'down' | 'left' | 'right'
function changeDirection(dir: TDir) {
  console.log(dir)
}
changeDirection('right')



export {}